24 Abstract of Paper on the Mouths nf Insects. 



world these insects render the locality uninhabitable to domestic 

 animals. 



2. Blowfly. Mandibles and maxillse suppressed, the labium 

 being the most highly developed part. The tube in this case is 

 much larger, and terminated by a pair of hollow sacs or labellae, 

 which are spread out when feeding, but at rest have their faces 

 united. The capillary canals are deeply sunk in their surfaces 

 till the labellsB are fully expanded, when their indented rigid 

 edges are slightly protruded above the surface, and form the 

 object usually labelled " teeth of a fly." 



Lepidopteea. — This order affords a good example of the great 

 development of some organs and the repression of others. The 

 most conspicuous is the familiar coiled antlia, with its large pro- 

 tecting palpi. Most writers regard the antlia as a development 

 of the maxillas, but Lowne points out that they are identical 

 with the paraglossae or tongue-sheaths of the bee. Each half of 

 the antlia is pierced with two tracheal tubes, the inner margin 

 being armed with a double row of teeth, so that when they are 

 thus interlocked a third tube is formed, up which the nectar is 

 pumped. The papillfe, which arm the tip of the antlia, are 

 doubtless organs of sense. In one of the illustrations of the 

 antlia at rest you will notice the undulating appearance of the 

 trachea, and also the spines outside said to be used in tearing 

 open the nectaries of flowers. 



PuLiciD^. — The most conspicuous organs in the fleas are the 

 maxillary palpi, which exceed any of the others in size. The 

 mandibles are finely serrated or toothed sette, the maxillae tri- 

 angular and sheath-like, the labrum a finely perforated toothed 

 process ; while the labial palpi are partly razor-like and partly 

 jointed in the more normal forms. 



Pediculid^.- — Owing to the extreme difliculty of detecting the 

 real character of this group, they were long thought to be man- 

 dibulate in their action, but it has recently been found tliat the 

 mouth-organs consist of a very easily retractile tubular labium, 

 which is thrust out in the process of sucking. It is armed near 

 the base with a series of hooks, and carries at the tip the repre- 

 sentative of the mandibles. 



